The story of Ultrasaurus begins in 1979 when two different dinosaur fossils were discovered and mistakenly attributed to a new gigantic sauropod dinosaur, Ultrasaurus. However, it was later revealed that the fossil known as "Ultrasaurus" was actually a specimen of Supersaurus, a distinct sauropod dinosaur. This confusion led to some uncertainty regarding the true identity of Ultrasaurus, as the second fossil had already been named as a different dinosaur, Ultrasauros.

Despite the taxonomic challenges, the original Ultrasaurus specimen has since been reclassified as a diplodocid dinosaur, which has significantly altered our understanding of this immense creature.

As a diplodocid dinosaur, Ultrasaurus is characterized by its long neck and tail, slender body, and relatively small head. The name "Ultrasaurus" is derived from its massive size, but it is essential to clarify that its current classification is not synonymous with the original concept of Ultrasaurus.

While the exact size estimation of Ultrasaurus is still debated due to its confusing history, it is believed to have reached lengths of around 85 to 100 feet (25 to 30 meters) or more, making it one of the largest dinosaurs to have ever walked the Earth. Being a massive dinosaur, Ultrasaurus would have faced fewer threats from predators due to its size and intimidating presence. It may have utilized its long neck to reach high foliage and its strong tail for defense, similar to other sauropods.

While the true identity of Ultrasaurus has been muddled by taxonomic confusion, its historical significance as an early contender for the title of the largest dinosaur adds to the allure of this fascinating creature